How to speak and practice Italian and French without mixing them up

My Mother Tongue is Persian and I can fluently speak English , 6 years ago I started to study French nad I never used it but it's about 6 months that I'm living in Italy and I'm going on well with Italian .. but when I'm trying to speak french I mix up the words and logic for the conjugation of the verbs , Now I want to practice both languages to keep them in high level , just don't know how ... is there any special method ?